1. Field of the Invention
This invention is concerned with the production of aromatic alcohols, and in particular with the selective production of 3-alkylphenols and 1,3-dihydroxybenzene.
2. Description of the Prior Art
The organic compound phenol has found many important industrial and medical applications over the years. It is valuable both as an intermediate in the manufacture of other compounds and as a useful material in its own right. Modern manufacturing processes are described in detail in the monograph by A. Dierichs and R. Kubicka, Phenole und Basen, Vorkommen und Gewinnung (Akademie-Verlag, Berlin, 1958).
3-Methylphenol is presently used in disinfectants, fumigants, photographic developers and explosives. Its potential as a phenolic resin for adhesives and other industrial products is large, particularly in view of some of the unique characteristics of this particular derivative of phenol, e.g., it is approximately three times more reactive then the parent phenol and has increased toughness, moisture resistance and reduced brittleness, all of which are very desirable properties. However, a major drawback to widened industrial applications for this compound has been its relatively high cost of manufacture. Japanese Pat. No. 8929 (1955) to Maesawa and Kurakano describes a process for obtaining this compound from coal tar. Its preparation from toluene is disclosed by Toland in U.S. Pat. No. 2,760,991. Another process, involving oxidation of o- or p-toluic acid, is described by Kaeding et al. in Ind. Eng. Chem. 53, 805 (1961). However, separation of the 3-methyl compound (bp 202.degree. C.) from the mixed product stream, a necessary step in the heretofore practiced synthetic processes, is at best a very difficult and expensive undertaking.
1,3-Dihydroxybenzene has, like phenol, found numerous uses in both the medical and industrial areas as an intermediate in the synthesis of other materials and also as a useful substance by itself. A common method for manufacturing this useful compound has been by fusing 1,3-benzenedisulfonic acid with excess sodium hydroxide.